Obj-C中的不可变数组NSArray常用方法

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// main.m

// nsarray

// Created by Mr.Juice on 15/4/3.

#import <Foundation/Foundation.h>

int main(int argc,const char * argv[]) {

//—————————————————不可变数组—————————————————————

Obj-C中的数组在使用时的注意事项：

1.数组中不能存放基本数据类型，只能存放对象

2.数组在使用时不能越界

3.一个数组中存放的对象类型必须一致

//1.数组的创建

NSString *s1 = @"zhangsan";

NSString *s2 = @"lisi";

NSString *s3 = @"王五";

NSArray *array1 = [[NSArrayalloc]initWithObjects:s1,s2,s3,nil];

NSLog(@"array1 = %@",array1);

NSLog(@"s3 = %@",s3);

//2.objectAtIndex: 通过下标取数组

NSString *s4 = [array1 objectAtIndex:2];

NSLog(@"s4 = %@",s4);

//3.count: 数组中元素的个数

NSUInteger i = [array1 count];

NSLog(@"%ld",i);

//4.containObject: 判断数组中是否包含某一个对象

BOOL isContain = [array1 containsObject:@"lisi"];

NSLog(@"%hhd",isContain);

//NSLog(@"%@",isContain);

//5.indexOfObject: 查找一个对象在数组中的下标位置

NSInteger index = [array1 indexOfObject:@"王五"];

if (index == NSNotFound) {

NSLog(@"没有此元素。");

}

else{

NSLog(@"index = %ld",index);

}

//6.componentsJoinedByString:使用连接符，将数组中的字符串拼接

NSString *joinString = [array1 componentsJoinedByString:@"-"];

NSLog(@"%@",joinString);

//componentsSeparatedByString: 字符串的分割

NSArray *separatString = [joinString componentsSeparatedByString:@"-"];

NSLog(@"%@",[separatStringdescription]);

//7.lastObject: 访问数组中的最后一个元素

NSString *laststr = [array1 lastObject];

NSLog(@"%@",laststr);

//8.arrayByAddingObject: 追加元素

NSArray *array2 = [array1 arrayByAddingObject:@"追加元素"];

NSLog(@"%@",array2);

//—————————————————————————数组的遍历—————————————————————————————

//1.普通方法

for (int i=0; i<[array2count]; i++) {

NSString *str2 = [array2 objectAtIndex:i];

NSLog(@"%@",str2);

}

//2.快速便利

for(NSString *str3in array1){

NSLog(@"str3 = %@",str3);

}

//—————————————————————数组的创建、访问的新语法——————————————————————

//1.创建数组

NSArray *array3 = @[s1,s2,s3];

NSLog(@"array3 = %@",array3);

//等价于：

//NSArray *array3 = [NSArray arrayWithObjects:s1,s2,s3,nil];

//2.使用下标访问数组

NSString *str4 = array3[1];

NSLog(@"%@",str4);

return 0;

}

//———————————————————————以下是运行结果———————————————————————————————

2015-04-03 22:46:00.691 nsarray[766:79263] array1 = (

zhangsan,

lisi,

"\U738b\U4e94"

)

2015-04-03 22:46:00.694 nsarray[766:79263] s3 =王五

2015-04-03 22:46:00.694 nsarray[766:79263] s4 =王五

2015-04-03 22:46:00.695 nsarray[766:79263] 3

2015-04-03 22:46:00.695 nsarray[766:79263] 1

2015-04-03 22:46:00.695 nsarray[766:79263] index = 2

2015-04-03 22:46:00.695 nsarray[766:79263] zhangsan-lisi-王五

2015-04-03 22:46:00.696 nsarray[766:79263] (

zhangsan,

lisi,

"\U738b\U4e94"

)

2015-04-03 22:46:00.696 nsarray[766:79263]王五

2015-04-03 22:46:00.696 nsarray[766:79263] (

zhangsan,

lisi,

"\U738b\U4e94",

"\U8ffd\U52a0\U5143\U7d20"

)

2015-04-03 22:46:00.696 nsarray[766:79263] zhangsan

2015-04-03 22:46:00.696 nsarray[766:79263] lisi

2015-04-03 22:46:00.697 nsarray[766:79263]王五

2015-04-03 22:46:00.697 nsarray[766:79263]追加元素

2015-04-03 22:46:00.697 nsarray[766:79263] str3 = zhangsan

2015-04-03 22:46:00.697 nsarray[766:79263] str3 = lisi

2015-04-03 22:46:00.697 nsarray[766:79263] str3 =王五

2015-04-03 22:46:00.697 nsarray[766:79263] array3 = (

zhangsan,

lisi,

"\U738b\U4e94"

)

2015-04-03 22:46:00.697 nsarray[766:79263] lisi

Program ended with exit code: 0

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